Haemostatic agents have been known for many years. A well know haemostatic agent, for example, is “Monsel's Solution”, first described as a aqueous liquid by the French pharmacist Leon Monsel in 1852 and used during the Crimean War. The principal of its action is the presence of a ferric ion, which is a strong protein precipitant, causing coagulation which mechanically seals smaller blood vessels at a wound site.
Other solutions of polyvalent metal ions such as Ferric Chloride, Silver Nitrate, Silver Chloride, Aluminium Chloride Hexahydrate, Aluminium Sulphate and Aluminium Acetate are also utilised as haemostatic agents, and their mode of action is similar.
Monsel's Solution is applied by topical application to superficial cuts, wounds and abrasions and is commonly used to stem blood flow after punch biopsies, skin biopsies, and removal of localised skin lesions by curettage. Other uses of this haemostatic agent include as a styptic used in colposcopy, including following cervical biopsy and vulval biopsies, in shave excision, nail fold biopsy, nail matricectomy and cerumen removal. It also has use for minor wounds and abrasions or use in any location where a rapid and convenient cessation of blood flow is required. Its use is not limited to small wounds as it has also been successfully utilised as a coagulant in large exposed skin wounds. A use has been found to stop uterine bleeding without the loss of fertility (Disu S, Rebello L, Atalla R, “The Use of Interuterine Monsel's Solution in Severe Hemorrhage After Evacuation of Retained Products of Conception: A Case Report” Am. J Obstet. Gynecol; 2007 February: 196(2): p 6-7) and it has been found to be less painful and more effective in haemostasis after clot extraction from thrombosed external haemorrhoids than Silver Nitrate (Jetmore A B, Heryer J W, Conner W E, “Monsel's Solution: A kinder and Gentler Hemostatic”, Dis Colon Rectum 1993; 36: 866-867). Dentists may use it during tooth extraction.
While Monsel's solution in its aqueous from is an effective haemostatic agent, it (or indeed other simple aqueous salts), is not entirely satisfactory in use. More particularly, it is a very acid solution and, because of its iron content, causes staining and other problems if it is spilled or runs off the wound onto surrounding tissues or, indeed, clothing. It must therefore be handled and applied with care. Additionally, because of its high concentration which approaches saturation, the solute is liable to crystallise out even on short term storage and especially if the solution is stored at low temperatures or allowed to evaporate.
Many commercial supplies include the warning to hold the styptic above 22° C. In some instances a “paste” is made of the Monsel's solution by allowing evaporation to take place on standing to provide the required viscosity. However, this is a very non-reproducible method and the crystallisation is not controllable.
Other salt solutions such as those of aluminium chloride hexahydrate in water or aqueous alcohol (ethanol or isopropyl alcohol) containing 20 to 70% w/v of the salt (calculated as the hydrated salt) are also used as haemostatic agents and have similar problems.
It would therefore be highly advantageous if a haemostatic agent could be provided that reduces and/or alleviates the problems with the existing products.